A variety of machines has been proposed and used for forming patties of plastic food material, especially of ground meat. Examples of such machines include those disclosed in the U.S. Pat. Nos. 3,293,688, 3,623,188, and 4,113,415.
The inventor of the present invention has developed improved methods and apparatus for making a patty of plastic food material, and especially of meat, that has improved characteristics. Examples of such improved methods and apparatus are disclosed in the copending U.S. patent application of Harry H. Holly entitled "Ground Food Patty and Method and Apparatus for Making Same," Ser. No. 25,031, filed Mar. 29, 1979. A type of improved patty disclosed in that patent application is formed from a plurality of discrete plugs or masses of food material which are packed together in an array to enclose or encompass air spaces in the interstitial regions. This type of patty promotes more rapid and uniform cooking of the patty and aids in retention of the cooking juices.
According to one method for making the above-described patty according to the above-referenced Holly patent application, the plastic food material is, among other things, forced through a plurality of cavities or apertures defined in a foraminous member. The material is forced from the foraminous plate into a mold cavity to form the patty of relatively high porosity.
Some food material, especially ground meat and the like, contains tissue fibers or strings of tissue which, during working of the material, tend to separate from the other components of the material and which, when the material is forced through apertures in a foraminous member, may lodge on the upstream side of the foraminous member. Unless the lodged tissue fibers are removed from time to time from the upstream side of the foraminous member, an undesirable buildup of tissue fibers may occur and hinder continued movement of the food material through the foraminous member.
In the above-referenced Holly patent application, the inventor discloses a method and apparatus for overcoming the problem of tissue fiber buildup on the upstream side of the foraminous member. Specifically, in one of the embodiments disclosed in that patent application, food material is first forced in one direction into and/or through the apertures of the foraminous member and is then subsequently forced in the opposite direction through the apertures of the foraminous member into a mold cavity to form the patty. When the patties are repeatedly made according to this cycle, any tissue fibers that may undesirably lodge on one side of the foraminous member during the movement of the material in one direction are subsequently dislodged by the movement of the material through the apertures in the second direction. In this way, tissue fibers are continually dislodged from either side of the foraminous member.
It would be desirable to provide a relatively simple method for forming relatively high porosity patties of plastic food material by forcing the food material through apertures in a foraminous member wherein tissue fibers may be at least intermittently dislodged from the foraminous member. Additionally, it would be desirable to provide a method and apparatus for effecting such a patty-making process wherein the amount of movement of the food material is reduced to a minimum so as to avoid undesirable effects of excessive working of the food material.